Depression

As discussed in the previous chapter, the physical basis of depression involves neurotransmitters in the brain. In the brain, the nerve cells do not touch. There are microscopic gaps between them called synapses. For a nerve impulse to travel from one nerve cell to another, the sending cell releases a tiny amount of one of the neurotransmitters, which transmits the signal to the second cell, and so on around the body. After a nerve impulse has been sent across a synapse, special enzymes clear away the neurotransmitter so that another impulse may be sent. Depression is strongly associated with abnormally low levels of certain neurotransmitters.

There is some proof that certain forms of depression may be inherited. Genes, tiny parts of cells that carry traits from parents to children, are the “recipe” for a new person. If you are born with genes that cause the body to produce too much or too little of certain hormones, you will have a chemical imbalance. This imbalance may put you at greater risk for depression. Manic-depression, or bipolar disorder, is the kind of depression that is most often inherited.

According to major studies of depression in children, it takes more than just genes for a person to suffer from depression. Life experiences affect a person's risk of developing depression as much as genetics. Research indicates that if genes have caused an imbalance of chemicals in your body, it may take only a little stress or physical illness to bring on depression. But if your body has a normal chemical balance, you may be able to handle much more stress without feeling depressed.